1. Field of the Invention
The present invention relates to a fire detection method and a fire detection apparatus and to a recording medium recorded with a fire detection program and a fire detection data, particularly to a technology for detecting at an initial stage of a fire which increases in humidity by heating among fires generated by heating some objects such as heat evolution of an apparatus due to overload or heat generation in electric wiring.
2. Description of Related ART
In a prior art fire detection method, smoke, heat, burning gas, or organic gas generated by a fire has been sensed. As such a fire detector, there is a smoke detector, a heat detector, a carbonic acid gas detector, a chlorine gas detector, or the like.
However, the above prior art fire detectors have the following problems which have yet to be solved. Specifically, since the smoke detector, heat detector, and the like sense smoke or heat which is necessarily generated during a fire, they are positive to find a fire, however, are low in sensitivity to find a fire in the stage of smoldering or baking before generating flame or smoke or smokeless burning. Further, the chlorine gas detector is high in sensitivity, however, all combustibles don't generate chlorine gas, and it cannot be a general-purpose fire detector.
On the other hand, in a facility having an expensive machine such as communications apparatus, it is necessary to positively sense a fire at an early time, possibly in the stage of smoldering or baking before generating flame or smoke or smokeless burning, and reduce the damage to a minimum.
Except for gasoline, explosive, or propane gas which is highly inflammable in itself, such materials as wood, paper, resins, and paints used in architectural materials or various indoor equipment and apparatus, when heated, first undergo a humidity change (humidity increase) by evaporation of water which adsorbed on the surface of the above materials before thermal decomposition. Therefore, in a fire generated by heating an object such as heat evolution due to overload of an apparatus or heat generation in electric wiring, there is a humidity increase in the stage of initial baking or smokeless burning, and the inventors have confirmed that, if this humidity increase can be detected, early detection of a fire becomes possible. Thus, the inventors have accomplished the present invention with this consideration.